1. Field of the Invention
The present invention relates to an apparatus and method for transmitting a broadcast signal, an apparatus and method for reproducing a broadcast signal, and a broadcast signal data structure.
2. Discussion of the Related Art
Generally, as analog broadcasting is replaced by digital broadcasting to transmit digital signals, the digital broadcasting is able to transmit additional image information, text and the like as well as images for a pure broadcast.
Yet, since the transmission bandwidth for a digital broadcast system or a digital communication system is limited, an object to be transmitted has a limitation in size.
In a broadcast system according to a related art, in case that a broadcast transmitting end transmits a series of images with a predetermined time interval, a broadcast receiving end is able to play back the images according to the same time interval and the same transmission sequence from a timing point delayed from the transmission timing point.
However, if a broadcast or communication system having a narrow bandwidth reproduces a transmitted object consuming a large bandwidth, a playback speed of the reproduced object is not equal to the transmission speed of the object. As a result, dynamism of the reproduced object is lowered.
Further, even if the broadcast receiving end is able to reproduce objects transmitted from the broadcast transmitting end, the broadcast receiving end is subject to the transmission speed or sequence of the objects transmitted by the broadcast transmitting end when reproducing the objects and thus there is a limitation on the types and configurations of contents that can be transmitted for an effective display.
For instance, the broadcast transmitting end may be able to transmit a 3-dimensional image or broadcast signals having various image configurations to attract the interest of the viewers at the receivers. However, according to the related art, this process is carried out in the same manner for all contents. Also, it is the broadcast transmitting end that generates the 3-dimensional images and broadcast signals having various image configurations and effects. As such, a heavy load of configuring to generate and transmit these images is put on the broadcast transmitting end, and the bandwidth problems are present at the transmitting end since these image need large bandwidths for transmission.
In addition, in the related art broadcast receiving apparatus and method, the broadcast receiving end has a problem in receiving such objects, transmitted by the broadcast transmitting end and reproducing the objects itself. For instance, if the transmission speed of the broadcast signal is slow or the bandwidth is limited, the broadcast receiving end is unable to properly receive, reproduce and display the objects, e.g., 3-dimensional images or images having special effects.